4.4-stable review patch. If anyone has any objections, please let me know.
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From: Oleg Drokin green@linuxhacker.ru
commit 8c7245abda877d4689b3371db8ae2a4400d7d9ce upstream.
Move the state selection logic inside from the caller, always making it return correct stp to use.
Signed-off-by: J . Bruce Fields bfields@fieldses.org Signed-off-by: Oleg Drokin green@linuxhacker.ru Signed-off-by: J. Bruce Fields bfields@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/nfsd/nfs4state.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-)
--- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -3420,13 +3420,14 @@ alloc_init_open_stateowner(unsigned int }
static struct nfs4_ol_stateid * -init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp, - struct nfsd4_open *open) +init_open_stateid(struct nfs4_file *fp, struct nfsd4_open *open) {
struct nfs4_openowner *oo = open->op_openowner; struct nfs4_ol_stateid *retstp = NULL; + struct nfs4_ol_stateid *stp;
+ stp = open->op_stp; /* We are moving these outside of the spinlocks to avoid the warnings */ mutex_init(&stp->st_mutex); mutex_lock(&stp->st_mutex); @@ -3437,6 +3438,8 @@ init_open_stateid(struct nfs4_ol_stateid retstp = nfsd4_find_existing_open(fp, open); if (retstp) goto out_unlock; + + open->op_stp = NULL; atomic_inc(&stp->st_stid.sc_count); stp->st_stid.sc_type = NFS4_OPEN_STID; INIT_LIST_HEAD(&stp->st_locks); @@ -3454,10 +3457,11 @@ out_unlock: spin_unlock(&oo->oo_owner.so_client->cl_lock); if (retstp) { mutex_lock(&retstp->st_mutex); - /* Not that we need to, just for neatness */ + /* To keep mutex tracking happy */ mutex_unlock(&stp->st_mutex); + stp = retstp; } - return retstp; + return stp; }
/* @@ -4260,7 +4264,6 @@ nfsd4_process_open2(struct svc_rqst *rqs struct nfs4_client *cl = open->op_openowner->oo_owner.so_client; struct nfs4_file *fp = NULL; struct nfs4_ol_stateid *stp = NULL; - struct nfs4_ol_stateid *swapstp = NULL; struct nfs4_delegation *dp = NULL; __be32 status;
@@ -4297,16 +4300,10 @@ nfsd4_process_open2(struct svc_rqst *rqs goto out; } } else { - stp = open->op_stp; - open->op_stp = NULL; - /* - * init_open_stateid() either returns a locked stateid - * it found, or initializes and locks the new one we passed in - */ - swapstp = init_open_stateid(stp, fp, open); - if (swapstp) { - nfs4_put_stid(&stp->st_stid); - stp = swapstp; + /* stp is returned locked. */ + stp = init_open_stateid(fp, open); + /* See if we lost the race to some other thread */ + if (stp->st_access_bmap != 0) { status = nfs4_upgrade_open(rqstp, fp, current_fh, stp, open); if (status) {